A wrench is a hand tool for wrenching a nut/bolt. The applicant's U.S. Pat. No. 6,009,778, entitled “structure of open end wrench”, discloses an open-end wrench 10 as shown in FIG. 1. The open-end wrench 10 has a first jaw 12 and a second jaw 15. Seven continuously arranged teeth 14 are disposed on the holding face of the first jaw 12. A raised section 16 is disposed on the holding face of the second jaw 15. In use, the two jaws 12, 15 hold a threaded component 18 with the teeth 14 and the raised section 16 abutting against two sides of the threaded component to wrench the threaded component.
In practice, the above structure has some shortcomings as follows:
First, when wrenching the threaded component, the innermost tooth 14a of the first jaw 12 will bear a considerably great stress and is apt to break. This will deteriorate the wrenching effect of the wrench.
Second, the two innermost teeth 14a, 14b of the jaw 12 are quite adjacent to the corner 19 of the threaded component 18. The teeth have sharp tips, which tend to thrust into the side 181 or the corner 19 of the threaded component. As a result, it often takes place that the wrench is stuck with the threaded component and hard to separate therefrom.
Third, the innermost tooth 14a is engaged with the corner 19 of the threaded component 18 and tends to damage the corner 19.